A box-diagram model is presented in which we assume that the exotic exchange reaction ${\pi }^{-}p\to {\Sigma }^{-}{K}^{+}$ occurs as a result of multiple nonexotic exchanges, e.g., ${\pi }^{-}p\to {\rho }^{0}n\to {\Sigma }^{-}{K}^{+}$, and each step of this process is evaluated under $t$-channel single-pole approximations. The imaginary part thus obtained when multiplied by the real contributions of one-particle-exchange diagrams accounts for the main features of the polarization data of ${\Sigma }^{-}$.

Close

PrevNext

View figure in article